Window and panel frame structure

ABSTRACT

A frame structure for supporting window and panel materials, wherein the frame structure comprises a vertical mullion assembly and a horizontal transom assembly joined together to form various sized frame-supporting structures. Both the mullions and transoms are formed from elongated channel-like extrusions adapted to receive different sized windows and panels, particularly for construction of outer walls of buildings. The windows and panels alike are locked into place by a snap-in casing that is accommodated in both the mullions and transoms. The transom assembly is secured in and supported by the upright mullion assembly, which when assembled together form a box-like frame structure having the windows and panels supported therein.

United States Patent [1.91

Farley 51 June 5, 1973 541 WINDOW AND PANEL FRAME STRUCTURE PrimaryExaminerPrice C. Faw, Jr. [76] Inventor: Walter J. Farley, 2328 MonteraAmmey FranclS xLojaconosr' Drive, Hacienda Heights, Calif. [57] ABSTRACT[22] filed: June 1971 A frame structure for supporting window and panel[2]] App]. No.: 155,109 materials, wherein the frame structure comprisesa [52] US. Cl. ..52/476, 52/235, 52/498 Supporting Structures Both themulhons and transoms [51] IIIILCI. ..E04b 2/88 are formed from elongatedchanneblike extrusions [58] Field of Search ..52/235, 241, 476, adaptedto receive different sized windows and panels 52/495, 496, 498, 401,502, 731, 732 particularly for construction of outer walls of buildings.The windows and panels alike are locked [56] References C'ted into placeby a snap-in casing that is accommodated in UNITED STATES PATENTS boththe mulhons and transoms. The transom assembly 18 secured in andsupported by the upright 3,403,491 /1968 Eichmap. ..52/476 mullionassembly, which when assembled together 3,140,763 7/1964 E e n... form abox-like frame structure having the windows $053,353 9/1962 Mlllfil andpanels upported [herein 3,081,849 3/1963 l-lubbard..... 3,147,518 9/1964Horgan ..52/476 10 Claims, 10 Drawing Figures /Z I 28 m: #8 32 M0 8a I j86 5 //2{ I /4; 80 76 78 l 4 is 42 Z2 52 68 v f 4 /02 I. 70 //z' 50 /0 5Z6 56 54 w ma vertical mullion assembly and a horizontal transomassembly joined together to form various sized frame- BACKGROUND OF THEINVENTION 1. Field of the Invention This invention relates, generally,to window and panel frame structures and, more particularly, to framestructures formed of extruded channels.

2. Description of the Prior Art As is well known in the art, variousproblems and difficulties are encountered in providing suitable meansfor constructing large, substantially glass, outer walls of a building.The frame structure of such a wall at the present time is very costlydue to the many intricate components that are required to satisfactorilysupport the weight of the structure involved. Because of the fact thatthe glass windows used in this type of construction are quite large insize, the problem of static wind pressure is to be considered. If thewindow panes are not properly set within the frame structure, highstatic wind pressure will cause the panes and panels to shift back andforth, causing damage to the seals and, thus, allowing wind and rain toenter therethrough.

SUMMARY OF THE INVENTION The present invention comprises a window andpanel frame structure used as a curtain wall in the construction oflarge multi-floor buildings. The frame structure comprises a verticalmullion assembly and a horizontal transom assembly interlocked with eachother to form a box-like frame structure to support the window and- /orpanel, as required.

The mullion assembly comprises an elongated, extruded double-channelmember adapted to receive the vertical edges of different sized windowor panel thicknesses, which are held in place in the channels by asnap-in casing secured between the panel and one wall of the channelmember. Various sized ribs are integrally formed along the channel wallsand so designed as to permit the glass or solid panels to be easilyinstalled but, yet, capable of securing the panels from shifting underadverse conditions.

The transom assembly, which is interlocked and supported in the uprightmullion assembly and extends horizontally therefrom, is comprised of asingle extruded member which is reversibly fitted to an identicalextruded member to form an interlocked dual-channel support forreceiving the upper and lower edges of the various panes or panels. Toconform with the simplicity of construction, the upper and lower edgesof the panels are also secured within the dual channels by use of thesame snap-in casing that is provided in the mullion assembly.

The windows and panel sections are sealed within the channels by typicalglass bead seals, which also serve as a frictional holding means alongthe edges thereof.

Secured within the double channels of the mullions and transverselypositioned through the rib members of the channels are load-supportingpins, to provide a positive support for each transom assembly.

A second embodiment is included herein having the same mullions andtransoms as described above, except that the glass panes and panels arepositioned adjacent the opposite channel walls, wherein the normaloutside walls of the frame structure are reversed and become the innerframe portion having one of the snap-in cas ings formed with a flat,inwardly-extending, shelf-like member provided at its outer end, with adepending channel to receive and support an inner wall panel.

OBJECTS AND ADVANTAGES OF THE INVENTION The present invention has for animportant object a provision for supporting and securing window panesand/or panels of different sized thicknesses, without the requirement ofspecial components or tools.

It is another object of the invention to provide a window and panelframe structure that requires only three major extruded components.

It is a further object of the invention to provide a window and panelframe structure that is capable of supporting large panes and/or panels,and also preventing shifting of said panes and/or panels within theframe structure under high static wind pressure.

A still further object of the invention is to provide a frame structureof this character that is relatively inexpensive to manufacture.

Another object of the invention is to provide a frame structure of thischaracter having a mullion assembly with positive securing andsupporting means for each horizontal transom assembly.

A further object of the invention is to provide a frame structure ofthis character comprising extruded mullion assemblies and transomassemblies that are simple and easy to assemble, service and maintain.

Still another object of the invention is to provide a structure of thischaracter wherein the normal inside portion of the frameis capable ofbeing reversed to the outside, and vice versa, for the normal outsideportion of the frame.

Other characteristics, advantages and objects of this invention can bemore readily appreciated from the following description and appendedclaims. When taken in conjunction with the accompanying drawings, thisdescription forms a part of the specification wherein like referencesand characters designate corresponding parts in several views which areas follows:

DESCRIPTION OF THE DRAWINGS Referring more particularly to theaccompanying drawings, which are for illustrative purposes only:

FIG. 1 is a partial elevational view of a curtain wall structureincorporating the present invention;

FIG. 2 is an enlarged cross-sectional view taken on line 2-2 of FIG. 1thereof;

FIG. 3 is an enlarged cross-sectional view taken on line 3-3 of FIG. 1.

FIG. 4 is a transverse cross-sectional view of a mullion with the end ofa transom member secured and supported therein;

FIG. 5 is a cross-sectional view taken on line 5-5 of FIG. 4;

FIG. 6 is a similar view to that of FIG. 5, but showing a different typeof support means for the transom assembly;

FIG. 7 is a partial perspective view of the double channel extrusionmember of the mullion assembly;

FIG. 8 is a partial perspective view of an extruded member which formsthe transom assembly;

FIG. 9 is a partial perspective view of the snap-in cas; ing; and

FIG. 10 is a cross-sectional view similar to FIG. 3 showing analternative embodiment of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawings and,more particularly, to FIG. ll, there is shown a portion of a curtainwall, generally indicated at 10, representing an outside wall of amulti-story building structure. Generally, the curtain wall comprises aframe structure 12, supporting window panes 14 and panel members 16,which are shown positioned between the upper and lower ends of saidwindow panes 14.

The frame structure 12 includes a plurality of mullion assemblies, whichare the vertical portions of the frame structure 12, and transomassemblies that are horizon tally positioned between each uprightmullion structure, each assembly being indicated generally by referencenumerals l8 and 20, respectively.

The mullion assemblies comprise an elongated, double channeled, extrudedbeam member 22 having a somewhat central web wall 24. One portion of theweb wall 24 provides a partition 24a between channels 26 and 28,respectively, as indicated in FIGS. 2 and 7. The other part of wall 24extends outwardly, becoming an integral part of an outer wall 30, whichis formed normal to said wall 24, forming a somewhat T-shapedconfiguration. In order to strengthen the structural area of the walls30 and 24, there are provided flanges 32 and 34, inwardly bent along aparallel plane of the wall 24.

The extrusion in FIGS. 2 and 7 has the two channels 26 and 28 extendingin opposite directions and having a common channel bottom 24a, and sidewalls 36 and 37 formed at right angles to the bottom 24a for receivingthe edges of windows 14 in end-to-end relationship. Therefore, channel26 is formed by a portion of wall 36 and 37 as side walls thereof, andpartition 24a providingthe bottom wall. Channel 28 is also formed by oneportion of the walls 36 and 37, and partition 24a.

Referring first to channel 26, there is provided in that portion of thewall 36 an integral inwardly-formed support rib 38 extending along theentire length of the channel and having an oppositely-disposed supportrib 40 which is formed as an integral part of wall 37. These ribs arepositioned adjacent and parallel to the bottom wall 24, formingoppositely-arranged channels 42 and 44. There are provided in each innerface of walls 36 and 37 sealing and mounting grooves 46 and 48,respectively. Each of said grooves is positioned between the ribs 38 and40, and the outer edges 50 and 52 of the walls 36 and 37. The groovesare adapted to receive a sealing or packing means 54, generallycomprised of an elongated neoprene bead. It should be noted that thereare many kinds of seals and packings and any one might be used,depending on the particular construction requirements. When the window14 is placed within the channel 26, it is positioned against the sealingmeans 54 on one side and is forced to remain in a sealed relation bybeing locked into place by a snap-in casing, indicated generally at 56.The casing 56 is provided with a somewhat flexible lip member 58 whichis adapted to be received within channel 42, hooking behind rib 40 bymeans of shoulder 60, as seen in FIG. 2. This allows for a firm grip ofthe casing 56 when a flexible snap arm 62 is forced inwardly to engagemounting groove 46. The snap arm 62 extends inwardly from a flat wall 64of the casing 56 along one side thereof and is provided with anoutwardly-projecting tongue 66 which rests within the groove 46. Arm 62extends inwardly and upwardly from tongue 66 so that the casing can bemore readily received within the channel 26 and held in place by thetension between arm 62 and the opposite wall 68. Wall 68 is providedwith a similar sealing groove 70 therein, to accommodate another sealingmeans 54 which is thereby forced against the inner face of the window14. These sealing means 54 are additionally used to fixedly support thewindows in their respec tive channels.

Channel 28 is somewhat similar in construction to that of channel 26.However, an additional pair of oppositely-disposed ribs 72 and 74 areinterposed between smaller width ribs 76 and 78, respectively, and thebottom wall 24a. Said ribs 72 and 74 are arranged parallel to ribs 76and 78 but extend inwardly from side walls 36 and 37 a distance greaterthan ribs 76 and 78, thereby creating a very firm extension membercapable of carrying weights heretofore not capable of being carried byother structures.

It should be understood that, when the frame structure 12 is constructedand the mullions are in place,

Channel 26 of one mullion will be oppositely opposed to channel 28 ofthe adjacent mullion so as to provide a proper clearance when fittingeach window pane 14 or panel 16 therein. The fitting of each member,particularly a large window pane, is accomplished by inserting one ofthe vertical edges, such as indicated at 80, of the window 14 first intochannel 28, then passed and between the ribs 72 and 74, allowing room atthe opposite edge to easily pass about the adjacent mullion extrusion,at which time both edges of the window are p0- sitioned within eachrespective channel 26 and 28.

Channel 28 is also provided with sealing and mounting grooves 82 and 84,such as those in channel 26. The window 14 is locked into a fixed andsealed position along the outer portion of wall 37 of channel 28 bysealing bead 54 and held in place by snap-in casing 56, as previouslydescribed in relation to channel 26, with the exception, however, thatchannels 42 and 44 are formed by ribs 72 and 76, and 74 and 78,respectively.

As for weather protection and ornamental design, there are providedcover strips 86 and 88. Under normal construction the T-shaped portionof the extrusion is located on the outside of the building and exposedto weather and, therefore, would be covered by the somewhat U-shaped,thinly-extruded cover 86, made preferably of aluminum.

Along the outer free edges of the cover 86 there are formed protrudingshoulders which, when forced over the projecting ribs 102 of the wall37, snap into recess 104 along the outer face of each of said ribs 102.(See FIGS. 2 and 7) Cover 88 is snapped into position over the wall 36,which is generally located within the building structure. The covercomprises a substantially flat wall 106 having flanges 108 thatarecapable of snapping into position by means of lips 110, formed along theouter free edges of the flanges 108, which are adapted to be receivedwithin elongated matching recesses 112.

Referring now to FIG. 3, there is a cross-sectional illustration of theextrusions which comprise the transom assembly 20 of the frame structure12. The extrusions are generally indicated by reference numeral 114, asseen in FIG. 8, and have a configuration substantially that of a Tlaying on its side. In order to assemble a transom section, twoidentical pieces are cut from the a plurality of mullion assembliesvertically positioned and equally spaced in parallel relationship toeach other within said frame structure;

a plurality of transom assemblies horizontally positioned between eachof said mullion assemblies, said transom assemblies being spaced apartin a parallel predetermined distance;

a removable interlocking means between the outer free ends of saidtransom assemblies and said mullion assemblies; and

means for removably securing said window or panel members within saidmullion and said transom assemblies, wherein each of said mullionassemblies comprises: an elongated mullion extrusion member havingoppositely disposed dual channel members, each of said channels havingthe same bottom wall,

and at least one pair of parallel side walls extending therefrom,

said side wall being spaced apart with suitable clearance for saidwindow or panel members, and securing means to be inserted therebetween,

said side walls being provided ontheir inner faces with sealing groovesand longitudinal ribs, wherein said free ends of said transom assembliescan be removably engaged therewith, and

means provided within said ribs for supporting said interlocking means;and wherein each of said transom assemblies comprises:

a first transom extrusion member;

a second transom extrusion member identical to said first extrusionmember, both being reversibly fitted into each other;

oppositely-disposed dual channels formed by said reversibly-fittedextrusions, each channel having extending side walls suitably spacedapart to receive said securing means and said window or panel memberstherebetween, said walls being provided on their inner faces withintegral longitudinal support ribs and sealing grooves.

2. A curtain wall, as recited in claim 1, wherein said means forremovably securing said window or panel members within said mullion andsaid transom assemblies comprises:

a snap-in casing member adapted to be received in said channels of saidmullions and transom assemblies.

3. A channel wall as recited in claim 2, wherein said snap-in casingmember comprises:

a flat wall;

a depending side wall;

a sealing groove in said side wall; a lip member extending outwardlyfrom said side wall and adapted to frictionally engage at least one ofsais ribs within said channels of both assemblies; and

an arm member depending from the opposite side of a pair ofcorresponding notches provided within both ends of at least one of thetransom extrusions, said notches being positioned to receive oppositely;disposed ribs therein.

5. A curtain wall, as recited in claim 3, wherein said removableinterlocking means comprises:

an angle member removably mounted within each of said channels of saidmullion extrusions for sup porting the free ends of said transomassemblies thereon; and

a pair of notches, each of which is provided within oppositely-disposedribs of said channels of said mullion extrusions for supporting the freeends of said transom assemblies thereon; and

a pair of notches, each of which is provided within oppositely-disposedribs of said mulltion extrusions for receiving and supporting said anglemembers.

6. A curtain wall, as recited in claim 5, including:

means for sealing said window and panel members within said channels ofboth of said mullion and transom assemblies, said sealing means beingsecured within said sealing grooves of said channels and said casing.

7. A curtain wall, as recited in claim 6, including:

cover walls for covering said mullion and transom assemblies;

means for removably securing said cover walls to said mullion andtransom assemblies.

8. A curtain wall, as recited in claim 7, wherein the snap-in casingmember secured in one of said channels of said transom assemblycomprises:

a flat wall extending outwardly from said transom extrusion;

a depending side wall;

a sealing groove in said side wall;

a lip member extending outwardly from said side wall and adapted tofrictionally engage at least one of said ribs within said channel ofsaid transom assemy;

an arm member depending from said flat wall intermediate the dependingwall and the opposite edge of said flat wall, and provided with anoutwardlyextending shoulder for positive locking engagement with atleast one of said grooves; and

a depending channel member formed along the longitudinal outer free edgeof said flat wall.

9. A curtain wall, having a frame structure for supporting window andpanel members, comprising:

a plurality of mullion assemblies vertically positioned and equallyspaced in parallel relationship to each other within said framestructure;

a plurality of transom assemblies horizontally positioned between eachof said mullion assemblies, said transom assemblies being spaced apartin a parallel predetermined distance;

a removable interlocking means between the outer free ends of saidtransom assemblies and said mullion assemblies; and

means for removably securing said window or panel members within saidmullion and said transom assemblies, a casing member extending outwardlyfrom at least one of said transom assemblies, said casing membercomprising:

a flat, horizontal wall extending outwardly from said transom member andremovably secured thereto,

extrusion 114 and then reversibly fitted together, as shown in FIG. 3.Each member therein is referred to by reference characters 116 and 118,respectively. Since each member 116 and 118 is identical to extrusion114, a description of extrusion 114 should suffice.

FIG. 8 clearly illustrates that extrusion 1 14 comprises a structuralpartition 120 integrally formed along each opposite edge of walls 122and 124. The junction of the partition with wall 122 is positionedcloser to one outer edge of wall 122 than the opposite edge thereof.That is, the depending portion of wall 122, as seen in FIG. 8, issubstantially shorter than that of the upper portion. This allows for anenlarged channel 126 to be formed by rib member 128 extending inwardlyfrom said wall 122 and parallel to partition 120. A similar rib 130extends inwardly from the lower portion of wall 122 and forms a channel132 with the opposite side of partition 120, said channel 132 beingsmaller in width than channel 126. Sealing and mounting grooves 134 and136 are provided in the inner face of wall 122 along the outer paralleledges thereof.

Referring to FIG. 3, there is shown a cross-sectional view of anassembled transom 20, in which said assembly comprises a pair ofextrusions 116 and 118 being allochirally-arranged relative to eachother. That is, extrusions 116 and 118 are identical but oppositelyarranged so that one forms a right hand extrusion and the other forms aleft hand extrusion, whereby they can be interlocked to provideoppositely-disposed channels 138 and 140.

The interlocking of the extrusions 116 and 118 is accomplished when wall124 of each extrusion is forcefitted into the corresponding enlargedchannels 126.

The channel 138 faces upwardly from the transom assembly 20 in order toproperly receive the lower edge of window 14, and said channel 140 facesdownwardly therefrom to properly receive the upper edge of the panel 16.

The lower edge of said window 14 is secured between sealing beads 142and 144, respectively. The sealing bead 142 is held in place by beingadapted to be received in groove 134 of extrusion 116, while the sealingbead 144 is received in groove 70 of the snap-in casing 56.

The casing 56 covering the upper channel 138 is locked into positionwhen lips 58 and shoulder 60 are hooked between rib 128 of extrusion 116and partition 120 of extrusion 118, and tongue 66 is engaged withingroove 136 of extrusion 118.

In like manner, an additional casing 56 is snapped into place over thelower channel 140, securing panel 16 between sealing bead 146 and 148.

Both extrusions 1 16 and 1 18 are provided with shoulders 150 along theouter edges thereof for receiving lips 110 of cover plates 88, identicalto those used in the mullion assembly 18.

The mullion assemblies 18 and transom assemblies 20 are interlocked bymeans of dowel pins 152, as seen in FIGS. 3, 4 and 5. Said pins aremounted within holes 154 which are axially and sequentially aligned toeach other and transversely to said channels 26 and 28 of extrusion beam22. The pins 152 extend through the contiguous holes 154 so that eachfree end of the pins is adjacent the open sides of each channel 26 and28, thereby passing through channels 42 and 44, respectively, andpermitting the transom assembly to rest thereon when each free end ofsaid transom assembly is positioned within channels 26 and 28. One ofthe extrusions, such as extrusion 118, is provided with notches 156 and158, as shown in FIG. 4, so that the transom assembly can be slidablyreceived in channels 26 and 28 by allowing the notches 156 and 158 topass over ribs 38 and 40. When this occurs, legs 160 and 162 which areformed by the notches 156 and 158, respectively, are interposed withinchannels 42 and 44, thereby holding each transom assembly 20 from anylateral movement and providing a positive connection and a stable framestructure with a minimum amount of components.

In FIG. 6, there is shown an alternative arrangement, whereby the freeend of an extrusion 114 may be provided with a support means other thanpins 152. This arrangement comprises an angle member 164 having a flat,upper support wall 166 extending outwardly from said channels 26 and 28,and having a depending flange member 168. The flat wall 166 is removablysupported within notches 170 of the ribs 38, 40, 76 and 78.

ALTERNATIVE ARRANGEMENT Referring now to FIG. 10 in which ther is shownan alternative arrangement of the invention, it should be firstunderstood that in this arrangement the normal outside area of thecurtain wall 10, as previously described, is arranged to be inside thebuilding structure, whereby the normal inner area is now reversed. Toaccomplish this arrangement, the window panes and panels are nowpositioned and secured in the opposite sides of the channels 26, 28, 138and 140, as hereinbefore described. Then the snap-in casing 56, locatedin channel 138, is replaced by a snap-in casing, generally indicated at180, comprising a substantially inwardlyextending, upper flat wall 182,forming a shelf-like member having a depending flange member 184 adaptedwith a sealing groove 186 in which a typical sealing bead is received.Along the lower edge of the flange 184 there is provided a locking meanssimilar to that used in snap-in casing'56. Positioned inwardly fromflange 184 and depending downwardly from the flat wall 182 is a snap-inarm 188 for engagement with groove 136.

There is a depending channel member, indicated generally at 190,depending downwardly from the outer edge of the casing and extendinglongitudinally therewith to receive an inner partition or wall member192.

When wall 192 is placed within channel receiving member 190, a deadspace 194 is created between wall 192 and panel 16 in one direction, andfrom the level of the transom to the floor of the building in the otherdirection. This space 194 provides a means for locating hidden wires andpipes in the building.

The invention and its attendant advantages will be understood from theforegoing description and it will be apparent that various changes maybe made in the form, construction and arrangement of the parts of theinvention without departing from the spirit and scope thereof orsacrificing its material advantages, the arrangement hereinbeforedescribed being merely by way of example, and I do not wish to berestricted to the specific form shownor uses mentioned, except asdefined in the accompanying claims.

I claim:

1. A curtain wall, having a frame structure for supporting window andpanel members, comprising:

9 10 means for removably securing said casing member 10. A curtain wallas recited in claim 9 wherein said to said transom assembly, and formedalong one receiving member comprises a depending channel andlongitudinal edge of said flat wall, and includes a partition membervertically supported and a receiving member disposed along the opposite,received in said channel.

longitudinal, outer free edge of said flat wall. 5

1. A curtain wall, having a frame structure for supporting window andpanel members, comprising: a plurality of mullion assemblies verticallypositioned and equally spaced in parallel relationship to each otherwithin said frame structure; a plurality of transom assemblieshorizontally positioned between each of said mullion assemblies, saidtransom assemblies being spaced apart in a parallel predetermineddistance; a removable interlocking means between the outer free ends ofsaid transom assemblies and said mullion assemblies; and means forremovably securing said window or panel members within said mullion andsaid transom assemblies, wherein each of said mullion assembliescomprises: an elongated mullion extrusion member having oppositelydisposed dual channel members, each of said channels having the samebottom wall, and at least one pair of parallel side walls extendingtherefrom, said side wall being spaced apart with suitable clearance forsaid window or panel members, and securing means to be insertedtherebetween, said side walls being provided on their inner faces withsealing grooves and longitudinal ribs, wherein said free ends of saidtransom assemblies can be removably engaged therewith, and meansprovided within said ribs for supporting said interlocking means; andwherein each of said transom assemblies comprises: a first transomextrusion member; a second transom extrusion member identical to saidfirst extrusion member, both being reversibly fitted into each other;oppositely-disposed dual channels formed by said reversiblyfittedextrusions, each channel having extending side walls suitably spacedapart to receive said securing means and said window or panel memberstherebetween, said walls being provided on their inner faces withintegral longitudinal support ribs and sealing grooves.
 2. A curtainwall, as recited in claim 1, wherein said means for removably securingsaid window or panel members within said mullion and said transomassemblies comprises: a snap-in casing member adapted to be received insaid channels of said mullions and transom assemblies.
 3. A channel wallas recited in claim 2, wherein said snap-in casing member comprises: aflat wall; a depending side wall; a sealing groove in said side wall; alip member extending outwardly from said side wall and adapted tofrictionally engage at least one of sais ribs within said channels ofboth assemblies; and an arm member depending from the opposite side ofsaid flat wall and provided with an outwardly-extending shoulder forpositive locking engagement with at least one of said grooves.
 4. Acurtain wall, as recited in claim 3, wherein said removable interlockingmeans comprises: a pair of support pins fixedly mounted within thechannels of said mullion extrusions and extending outwardly from saidbottom wall of said channeLs to support the free ends of said transomassemblies thereon; and a pair of corresponding notches provided withinboth ends of at least one of the transom extrusions, said notches beingpositioned to receive oppositely-disposed ribs therein.
 5. A curtainwall, as recited in claim 3, wherein said removable interlocking meanscomprises: an angle member removably mounted within each of saidchannels of said mullion extrusions for supporting the free ends of saidtransom assemblies thereon; and a pair of notches, each of which isprovided within oppositely-disposed ribs of said channels of saidmullion extrusions for supporting the free ends of said transomassemblies thereon; and a pair of notches, each of which is providedwithin oppositely-disposed ribs of said mulltion extrusions forreceiving and supporting said angle members.
 6. A curtain wall, asrecited in claim 5, including: means for sealing said window and panelmembers within said channels of both of said mullion and transomassemblies, said sealing means being secured within said sealing groovesof said channels and said casing.
 7. A curtain wall, as recited in claim6, including: cover walls for covering said mullion and transomassemblies; means for removably securing said cover walls to saidmullion and transom assemblies.
 8. A curtain wall, as recited in claim7, wherein the snap-in casing member secured in one of said channels ofsaid transom assembly comprises: a flat wall extending outwardly fromsaid transom extrusion; a depending side wall; a sealing groove in saidside wall; a lip member extending outwardly from said side wall andadapted to frictionally engage at least one of said ribs within saidchannel of said transom assembly; an arm member depending from said flatwall intermediate the depending wall and the opposite edge of said flatwall, and provided with an outwardly-extending shoulder for positivelocking engagement with at least one of said grooves; and a dependingchannel member formed along the longitudinal outer free edge of saidflat wall.
 9. A curtain wall, having a frame structure for supportingwindow and panel members, comprising: a plurality of mullion assembliesvertically positioned and equally spaced in parallel relationship toeach other within said frame structure; a plurality of transomassemblies horizontally positioned between each of said mullionassemblies, said transom assemblies being spaced apart in a parallelpredetermined distance; a removable interlocking means between the outerfree ends of said transom assemblies and said mullion assemblies; andmeans for removably securing said window or panel members within saidmullion and said transom assemblies, a casing member extending outwardlyfrom at least one of said transom assemblies, said casing membercomprising: a flat, horizontal wall extending outwardly from saidtransom member and removably secured thereto, means for removablysecuring said casing member to said transom assembly, and formed alongone longitudinal edge of said flat wall, and a receiving member disposedalong the opposite, longitudinal, outer free edge of said flat wall. 10.A curtain wall as recited in claim 9 wherein said receiving membercomprises a depending channel and includes a partition member verticallysupported and received in said channel.